This invention relates to a fiber tuft feeder for supplying a textile fiber lap to a fiber processing machine such as a carding machine, a roller card unit or the like. The feeder is of the type which has a vertical first chute (upper or reserve chute), at the lower opening of which a feed roller is disposed, cooperating with an opening roller situated therebelow. From the opening roller, approximately tangentially thereto, a second chute (lower or feed chute) extends which is associated with a device which provides a densifying (fiber-compressing) air stream that passes through the fiber material situated in the feed chute. Such a fiber-compressing air stream flows along the opening roller, codirectionally with its direction of rotation.
According to a known apparatus, as disclosed in German Offenlegungsschrift (application published without examination) 39 12 565, an air outlet duct is provided for guiding a transporting air stream out of the upper chute after such transporting air stream deposited fiber tufts into the upper chute through an upper inlet thereof. In the air outlet duct a fan is disposed which branches off a partial air stream of the transporting air stream. Such a partial air stream proceeds along the cylindrical surface of the opening roller and subsequently flows tangentially to the opening roller to the clearance defined between the feed roller and the opening roller. During this occurrence, the air stream emanating from the fan and accelerated along the opening roller impinges upon the clearance and is abruptly braked thereby, causing a significant air turbulence. Such an undesired vortex generation is further amplified by the fact that the air stream generated by the fan is pulsating, that is, such an air stream is not uniform. Furthermore, the transporting air stream supplied to the fan is also fluctuating because of the fluctuating supply of fiber tufts in the upper chute. It is further disadvantage of the known arrangement that the air stream is significantly weakened by the clearance between the feed roller and the opening roller and thus its densifying (compressing) effect is adversely affected.